Low C4 as a risk factor for severe neuropsychiatric flare in patients with systemic lupus erythematosus

Relation between hydroxychloroquine dose and continuation rate in patients with systemic lupus erythematosus

OBJECTIVES

Hydroxychloroquine (HCQ) is recommended at a target dose of 5 mg/kg per actual body weight to reduce the risk of retinopathy in systemic lupus erythematosus (SLE). However, the efficacy of HCQ has been established at doses of 6.5 mg/kg per ideal body weight. This study aimed to clarify the effects of the HCQ dose on the continuation rate in Japanese patients, who generally have a lower body mass index than Western patients.

METHODS

This retrospective single-centre observational study enrolled patients with SLE on HCQ therapy. Patients were divided into two groups with a dose per actual body weight [the low-dose (<5 mg/kg) group and the high-dose (≥5 mg/kg) group], and continuation rates were compared. The efficacy of 1-year HCQ therapy was assessed in patients without additional immunosuppressive agents and biologics.

RESULTS

Of the 231 patients enrolled, 48 (20.8%) discontinued HCQ. The HCQ dose per actual body weight was identified as an independent risk factor for discontinuation. The low-dose group showed a significantly higher 1-year HCQ continuation rate than the high-dose group (83.2% vs. 72.8%, respectively). Both groups showed reductions in glucocorticoid requirement and serological activity after 1-year HCQ therapy.

CONCLUSIONS

HCQ <5 mg/kg per actual body weight may facilitate greater continuation.

Determinants of neuropsychiatric flares in patients with systemic lupus erythematosus: results from five phase III trials of belimumab

OBJECTIVE

To identify determinants of neuropsychiatric (NP) flares in patients with SLE treated for active SLE yet no ongoing severe NPSLE with non-biologic standard therapy plus belimumab or placebo.

METHODS

We analysed data from five phase III trials (BLISS-52, BLISS-76, BLISS-NEA, BLISS-SC, EMBRACE; n = 3638) after exclusion of patients with baseline NP BILAG A. Factors associated with NPSLE flare, defined as a new NP BILAG A or B, were investigated using Cox regression. In a subgroup analysis, we studied patients with baseline NP BILAG E for determinants of de novo NPSLE flare. Organ damage was assessed using the SLICC/ACR Damage Index (SDI).

RESULTS

We documented 105 (2.9%) NPSLE flares. In multivariable analysis, male sex (HR = 2.37; 95% CI: 1.31, 4.28; P = 0.004), baseline NP BILAG B-D (HR = 5.91; 95% CI: 3.86, 9.06; P < 0.001), and increasing SDI scores (HR = 1.35; 95% CI: 1.21, 1.50; P < 0.001) were strongly associated with NPSLE flare. Belimumab use yielded no association at any dose or administration form. In analysis of SDI domains, NP damage was the strongest determinant of NPSLE flare (HR = 3.25; 95% CI: 2.72, 3.88; P < 0.001), holding true for cognitive impairment (HR = 14.29; 95% CI: 9.22, 22.14; P < 0.001), transverse myelitis (HR = 21.89; 95% CI: 5.40, 88.72; P < 0.001), and neuropathy (HR = 8.87; 95% CI: 5.59, 14.09; P < 0.001). Male sex was the strongest determinant of de novo NPSLE flare (HR = 3.26; 95% CI: 1.51, 7.04; P = 0.003).

CONCLUSION

Male sex, NPSLE history, and NP damage were strong determinants of impending NPSLE flare. No clear protection or predisposition was conferred from add-on belimumab.

Association between Inflammation and Thrombotic Pathway Link with Pathogenesis of Depression and Anxiety in SLE Patients

As a complication of systemic lupus erythematosus (SLE), the neuropsychiatric form may manifest with neurological and psychiatric symptoms. Diagnosing neuropsychiatric SLE can be challenging due to the heterogeneity of this disease manifestation and the possibilities of investigation. This research aims to identify the possible associations between inflammation and thrombotic biomarkers alongside anxiety and/or depression manifestations in SLE patients. A group of 65 outpatients were investigated regarding the levels of depression, anxiety, disability, quality of life and other specific serum biomarkers linked with inflammation or coagulopathies. The results showed severe depression in eight participants, moderate depression in 22 (33.85%), and 26 (40%) subjects with mild depression. Anxiety was more prevalent within 64 participants (98.46%), while a degree of disability was reported by 52 participants (80%). Quality of life evaluated by EQ5D revealed a medium value of 1.57, and EQ5D VAS health medium value was 57.95 and was correlated with anxiety. A strong positive correlation between depression, anxiety and antibodies associated with anti-cardiolipin and anti beta2 glycoprotein I antibodies, lupus anticoagulant, ICAM-1, low C4 a and anti-ribosomal P antibodies were identified. These data results suggest that autoimmune/inflammatory and ischemic/thrombotic pathways could contribute to depression and anxiety as neuropsychiatric SLE manifestations.

Inhibitor of NF-κB Kinase Subunit ε Contributes to Neuropsychiatric Manifestations in Lupus-Prone Mice Through Microglial Activation

OBJECTIVE

Systemic lupus erythematosus (SLE) is a systemic autoimmune disease characterized by multiorgan dysfunction. Neuropsychiatric SLE (NPSLE) occurs in 30-40% of lupus patients and is the most severe presentation of SLE, frequently resulting in limitation of daily life. Recent studies have shown that microglia, tissue-resident macrophages in the central nervous system, are involved in the pathogenesis of NPSLE. This study was undertaken to explore new therapeutic targets for NPSLE focusing on microglia.

METHODS

RNA sequencing of microglia in MRL/lpr, lupus-prone mice, as well as that of microglia cultured in vitro with cytokines were performed. A candidate gene, which could be a therapeutic target for NPSLE, was identified, and its role in microglial activation and phagocytosis was investigated using specific inhibitors and small interfering RNA. The effect of intracerebroventricular administration of the inhibitor on the behavioral abnormalities of MRL/lpr was also evaluated.

RESULTS

Transcriptome analysis revealed the up-regulation of Ikbke, which encodes the inhibitor of NF-κB kinase subunit ɛ (IKBKε) in both microglia from MRL/lpr mice and cytokine-stimulated microglia in vitro. Intracerebroventricular administration of an IKBKε inhibitor ameliorated cognitive function and suppressed microglial activation in MRL/lpr mice. Mechanistically, IKBKε inhibition reduced glycolysis, which dampened microglial activation and phagocytosis.

CONCLUSION

These findings suggest that IKBKε plays a vital role in the pathogenesis of NPSLE via microglial activation, and it could serve as a therapeutic target for NPSLE.

Complement as a Biomarker for Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is a disease of immune complex deposition; therefore, complement plays a vital role in the pathogenesis of SLE. In general, complement levels in blood and complement deposition in histological tests are used for the management of SLE. Thus, the evaluation of complement status can be useful in the diagnosis of SLE, assessment of disease activity, and prediction of treatment response and prognosis. In addition, novel complement biomarkers, such as split products and cell-bound complement activation products, are considered to be more sensitive than traditional complement markers, such as serum C3 and C4 levels and total complement activity (CH50), which become more widely used. In this review, we report the complement testing in the management of SLE over the last decade and summarize their utility.

Anti-ganglionic nicotinic acetylcholine receptor α3 subunit antibody as a potential biomarker associated with lupus enteritis

OBJECTIVES

We aimed to identify the clinical significance of anti-ganglionic nicotinic acetylcholine receptor α3 subunit (gAChRα3) antibodies (Abs) in patients with systemic lupus erythematosus (SLE).

METHODS

This retrospective study comprised adult patients with SLE who visited our hospital from 2006 through 2019. Anti-gAChRα3 Abs were measured in the sera of patients with SLE using a luciferase immunoprecipitation system assay. The clinical features of the patients with or without anti-gAChRα3 Abs were compared. We evaluated whether the Abs predict a specific manifestation and affect its development or relapse rate.

RESULTS

Among 144 patients, anti-gAChRα3 Abs were detected in 29 patients. Lupus enteritis (LE) was more frequently seen in anti-gAChRα3 Ab-positive patients than negative patients. The levels of anti-gAChRα3 Abs were significantly higher in patients with LE than those with other lupus manifestations. Logistic regression analysis revealed the anti-gAChRα3 Abs were independent predictors for LE (odds ratio 6.2, 95% confidence interval 1.9-20.3, p = .002). Kaplan-Meier analysis showed the rate of LE development or relapse from the time of sera collection was higher in anti-gAChRα3 Ab-positive patients than in negative patients (p < .001).

CONCLUSION

Anti-gAChRα3 Abs could be a predictive biomarker for the development or relapse of LE.

Determination of the Risk Factors Contributing to the Development of Neuropsychiatric Lupus in a Systemic Lupus Erythematosus Cohort

Background

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease with a complex, varied clinical presentation that is both more common and has poor outcomes in women of color. SLE outcomes also seem to be influenced by socioeconomic factors. Neuropsychiatric lupus (NPL) is a common manifestation of SLE that is difficult to diagnose and treat and has poor clinical outcomes. There is no clear relationship between NPL and SLE-related autoantibodies, and this contributes to the difficulty in diagnosing NPL. As a result, NPL is a significant contributor to morbidity and mortality in patients with SLE.

Objective

The purpose of this study was to examine the relationship between serological and socioeconomic factors in the development of NPL in our patient cohort and determine the risk factors for the development of NPL.

Methods

This was an SLE single-center, retrospective chart review study that was performed at a university-based tertiary referral center. Patients aged 18 and older who meet the American College of Rheumatology (ACR) 1997 criteria and were seen between June 1st, 2015, and June 1st, 2019, were included in this study. Overall, 629 patients with SLE were identified, and 263 patients were included. Demographic and serological data were collected. Supplemental socioeconomic information for each zip code in Southwest Virginia was obtained from the United States Government Census website. Continuous variables were analyzed using the T-test or Mann-Whitney U test. Categorical variables were analyzed using chi-square tests or Fisher’s exact tests. Statistical analysis was performed using SAS9.4, and p-value < 0.05 was considered statistically significant.

Results

We reviewed a number of risk factors including age, sex, race, and median household income (MHI), noting no statistical relationship between these factors and the diagnosis of NPL. We did find that the presence of antiphospholipid antibodies (aPL) was significantly associated with a diagnosis of NPL and that complement 4 (C4) levels trended toward statistical significance.

Conclusion

In our cohort of patients, there was no relationship between age, sex, race, and median household income, and the diagnosis of NPL. There was a statistically significant relationship between aPL and the diagnosis of NPL. Other SLE-related antibodies showed no statistical relationship with the diagnosis of NPL. Although not statistically significant, there was a trend toward significance between complement 4 (C4) levels and the diagnosis of NPL.

Amino Acid Metabolism in Lupus

T cell metabolism is central to cell proliferation, survival, differentiation, and aberrations have been linked to the pathophysiology of systemic autoimmune diseases. Besides glycolysis and fatty acid oxidation/synthesis, amino acid metabolism is also crucial in T cell metabolism. It appears that each T cell subset favors a unique metabolic process and that metabolic reprogramming changes cell fate. Here, we review the mechanisms whereby amino acid transport and metabolism affects T cell activation, differentiation and function in T cells in the prototype systemic autoimmune disease systemic lupus erythematosus. New insights in amino acid handling by T cells should guide approaches to correct T cell abnormalities and disease pathology.